Protocols for Handling, Tagging, and Measuring Marine Turtles
The Cooperative Marine Turtle Tagging Program (CMTTP) is a centralized tagging program developed to distribute tags, manage tagging data, and facilitate exchange of tag information. The CMTTP is managed by the Archie Carr Center for Sea Turtle Research (ACCSTR) at the University of Florida and is funded by the National Marine Fisheries Service Southeast Fisheries Science Center.
The following guidelines describe the protocols for handling, tagging, and measuring marine turtles recommended by the CMTTP to avoid harming the turtles and to improve tag retention. For more information, see the chapters on tagging sea turtles (by G.H. Balazs) and measuring sea turtles (by A.B. Bolten) from Research and Management Techniques for the Conservation of Sea Turtles (Eckert, K.L., K.A. Bjorndal, A.F. Abreu-Grobois, and M. Donnelly editors, 1999, published by the IUCN Marine Turtle Specialist Group) and the document Recommendations for Activities Involving Brief Captivity with Non-Invasive or Minimally Invasive Procedures by L.H. Herbst and E.R. Jacobson.
Protocols for Handling and Tagging Turtles
- Handling and tagging turtles can result in introduction or transmission of disease among turtles. Use appropriate techniques and disinfectants, as described in the recommendations by Herbst and Jacobson, to avoid harming the turtles.
- When tagging turtles on nesting beaches, wait until the turtle has completed egg-laying before tagging or measuring the turtle.
- Tags should be cleaned of the oily residue from manufacturing in hot soapy water, rinsed in alcohol, and stored in sealed plastic bags until used.
- Due to tag loss, double tagging (one tag on each of two flippers) is now standard procedure. Place the tag within the molded surface of the applicator, and attach the tag to the trailing edge of the flipper. Attach the tag on the flipper so that it extends slightly from the edge of the flipper. On front flippers, the tagging site is the first or second large scale on the posterior edge of the flipper. Some researchers use the site proximal to and adjacent to the first large scale or between the two large scales. On hind flippers, the tagging site is the first large scale. Some researchers use the site proximal to and adjacent to the first large scale.
- Once the tag has been attached, check the tip to be sure it has properly cinched. The tag tip should overlap the edge of the hole by at least 3 mm. If the overlap is insufficient, carefully fit the tag back into the applicator and apply greater pressure. If this is still unsatisfactory, remove and apply another tag. This is important; improperly cinched Inconel tags are shed quickly.
- Refer to the chapter by G.H. Balazs for more details on tagging sea turtles.
- Submit annual reports with data for tagged turtles to ACCSTR. Follow the CMTTP Data Submission requirements as indicated.
- Inconel tags are expensive, so please take care of them and do not pass them on to other researchers. CMTTP tags must not be redistributed. At the end of the project, return all unused tags and applicators to the ACCSTR. Do not use CMTTP tags to mark stranded carcasses on the beach.
- Maintain the tag applicators so they continue to function properly. The salt environment is very corrosive and frequent application of a light lubricant (e.g., WD40) to the spring and pivotal surface is necessary, particularly when storing for long periods between seasons. Be careful not to contaminate the tags with lubricant. The applicators are expensive, and the CMTTP cannot replace them each year.
Protocol for Measuring Turtles
- Accurate and precise measurements are critical. Because a number of different measurements have been used in studies of sea turtles, it is essential to note specifically which measurements and which units are used (cm or inches; cm is the preferred unit). The terms used below are defined in the chapter on measuring sea turtles by A.B. Bolten. Refer to that chapter for more details on measuring sea turtles.
- The standard measure of carapace length for the CMTTP has been straight carapace length notch to tip (SCLn-t) measured from the anterior point at midline (nuchal scute) to the posterior tip of the supracaudals. Because the posterior tips of thesupracaudals are frequently broken in juveniles or worn away in adults, minimum straight carapace length (SCLmin; also referred to as SCLnotch-notch) measured from the anterior point at midline (nuchal scute) to the posterior notch at midline between the supracaudals is recommended as the standard measurement in the MTSG techniques manual (see chapter by A.B. Bolten). Investigators should measure SCLmin in addition to SCLn-t to facilitate comparisons among studies in the future.
- If calipers are not available, curved carapace length should be measured with a flexible tape measure. Curved carapace length notch to tip (CCLn-t) has been the standard CCL measure for the CMTTP and is measured from the anterior point at midline (nuchal scute) to the posterior tip of the supracaudals. Minimum curved carapace length (CCLmin; also referred to as CCLnotch-notch) is measured from the anterior point at midline (nuchal scute) to the posterior notch at midline between the supracaudals. CCLmin is recommended as the standard measurement in the MTSG techniques manual (see chapter by A.B. Bolten) because the posterior tips of the supracaudals are frequently broken in juveniles or worn away in adults and because there is greater variability in CCLn-t as a result of the unpredictable way that the tape measure deviates from the midline. Investigators should measure CCLmin in addition to CCLn-t to facilitate comparisons among studies in the future.
- To avoid confusion, be sure to specify the method (straight or curved) and the measurement taken (SCLn-t or SCLmin or CCLn-t or CCLmin).
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